Research on Pickering emulsification technology based on the concept of “combination of medicine and adjuvant” to improve the pH stability of volatile oil in solid preparations—taking Lingzhu Pulvis as an Example

Abstract

Lingzhu Pulvis are widely used in clinical practice because of their therapeutic effects, but their stability and efficacy are affected by the easy oxidation and volatility of Acorus calamus. In this study, we combined the idea of “combination of medicine and adjuvant” and introduced Pickering emulsion technology to use the ingredients of Lingzhu Pulvis as the stabilizer of Pickering emulsion. Pearl powder was selected as the stabilizer by the type of emulsion formation and the state of emulsion layer, and the optimal preparation method was 0.065 g·ml− 1 of pearl powder and 45% oil, prepared using high-pressure homogenization method (500 bar, three times). The malondialdehyde and peroxide contents in the crude oil and Pickering emulsion groups were analyzed under different pH environments, and it was clear that the Pickering emulsion group possessed higher antioxidant properties. The volatile oil of Acorus calamus in different groups was analyzed using GC-MS, and seven differential components were screened by processing the analytical data with R language, which were further determined that the differential components changed more slowly and had significantly improved stability in the Pickering emulsion group. This study provides a reference for the improvement of stability of other solid formulations containing oil in Chinese medicine.